Conditioning shampoos both clean and condition the hair in one step. However, prior means of achieving both the cleansing and the conditioning of hair in one step are problematic. Normally the conditioning agent, frequently a siloxane, will wash out with the rinse water because of the detersive action of surfactants also incorporated into the shampoo. In order to solve this problem, deposition agents such as cationic polymers may be combined with the conditioning agent in the shampoo to more effectively bind the conditioning agent onto the hair and thus resist wash out in the rinse cycle. Such combinations are disclosed in U.S. Pat. Nos. 5,573,709, 5,977,038, 6,200,554, 6,451,298 and 5,302,322 and U.S. Application Publication Nos. 2006/0123564 and 2005/0002871 herein incorporated entirely by reference.
This solution, however, is not entirely adequate and there is still much room for improvement in conditioning shampoos. For example, many cationic polymers tend to build up on the hair and to result in an undesirable, “unclean” coated feel. Cationic polymers therefore, conventionally, are preferably used at limited levels to minimize this problem. This, however, can limit the overall conditioning benefits that are obtained. Furthermore, the use of two separate ingredients (cationic polymer and silicone) has a high adverse impact on cost of the shampoo formulation; the levels of hair conditioning wet lubricity are not comparable to those obtained from a rinse off conditioner and frequently the silicone/cationic polymers complex in the shampoo giving an opaque formulation.
The presently disclosed amphiphilic block copolymer comprising polysiloxane and polycationic blocks resolves many of the above problems associated with the present state of the art for conditioning shampoos.
Amphiphilic block copolymers are however, generally known for use in cosmetics. These amphiphilic block copolymers comprise hydrophobic and hydrophilic segment and are described in U.S. Application Nos. 2003/0225168, 2004/0039101, 2004/0009136, 2006/0217285 and 2004/0202634 herein incorporated entirely by reference.
Cationic functionalized polysiloxanes are also known and are disclosed in Japanese unexamined Application Nos. JP1995002964 and JP1998291967 and PCT Application No. WO99/32539. These modified polysiloxanes are known for use as conditioning agents in hair bleach or dye compositions such as disclosed in U.S. Application Publication No. 2006/0123564 herein incorporated entirely by reference.
Furthermore, block copolymers formed from polysiloxanes and polycationic segments are known such as those described in U.S. Pat. No. 5,760,136 herein incorporated entirely by reference. This reference does not disclose block copolymers comprising polysiloxane blocks and polycationic blocks derived from diallydialkylammonium monomers.
Thus, the inventors believe the presently disclosed amphiphilic block copolymers formed from polysiloxanes and a polycationic blocks wherein the polycationic block is derived from diallydialkylammonium monomers to be novel and to provide optimal cleaning and conditioning of keratinous substrate (hair and skin) while reducing the number of undesirable side effects that can result from conditioning agent build-up.